The disclosure of U.S. patent application Ser. No. 09/378,121 is incorporated herein by reference.
The present invention relates to coiling machines, although other uses will be apparent from the teachings disclosed herein. In particular, the present invention relates to coiled spring assemblies produced in a unified process. A specific embodiment of the coiled spring assemblies includes coiled ferrite spring assemblies which are of particular use in the automotive industry for reduction of electromagnetic interference (EMI) during ignition system firing.
Spring coiling machines are well known in the art. Spring coiling machines and methods are discussed in U.S. Pat. No. 5,036,690, entitled xe2x80x9cFlexible Pipe End Crimping Apparatus,xe2x80x9d issued Aug. 6, 1991; U.S. Pat. No. 5,452,598, entitled xe2x80x9cAutomatic Spring Formation Apparatus,xe2x80x9d issued Sep. 26, 1995; and U.S. Pat. No. 5,791,184, entitled xe2x80x9cSpring-Making Machine,xe2x80x9d issued Aug. 11, 1998. U.S. Pat. Nos. 5,036,690; 5,452,598; and 5,791,184 are incorporated herein, in their entirety, by reference. It is also known in the art to provide inserts in springs.
It has, however, been difficult to manufacture spring assemblies with plugs in a single continuous or unified process. Generally, the insert might be maintained in place by crimping the coils around the insert or inserting wire or flat stock about the ends of the coil to hold down the insert within the coil. These and other prior art methods for producing coiled plugs usually require inserting the plug into the coil after the coil is produced as a finished product. For example, the spring is manufactured, then in a separate process the cylinder is inserted into the spring (typically xe2x80x9cby handxe2x80x9d). And then, in another separate process, the cylinder is secured in the spring by one of the aforementioned methods. These prior art methods involve multiple separate steps, often done by hand, and as a result have reliability and efficiency problems associated with them.
The present invention overcomes these problems and provides advantages heretofore unattainable.
The present invention relates to coiling machines and springs generally. It more particularly relates to machines and methods for manufacturing spring assemblies having a core inserted into the coil. The core may be one or more elements and the assemblies may have a variety of configurations. Accordingly, one object of the present invention is to provide a new and improved spring coiling machine.
Another object is to provide a consistent and reliable method of manufacture coiled spring assemblies at a reduced cost.
Another object of the present invention is to provide methods of manufacturing coiled spring assemblies in a unified manufacturing process.
Yet another object is to provide an improved spring assembly.
Another object of the present invention is to provide a continuous coiled spring assembly manufacturing process and apparatus for same.
Accordingly, one embodiment of the present invention is a coiling machine. The coiling machine includes a coiler adapted to form a coil having a first diameter and a second diameter. The second diameter is preferably smaller than the first diameter. Although not required for all applications, multiple diameters are preferred, including substantially equal (or uniform) multiple diameters. An insert device is positioned to insert a core into the coil, wherein the core has a core diameter between the first diameter and the second diameter, e.g. the core is smaller than the first diameter and larger than the second diameter. Thus, the core may be contained in one diameter (the first diameter) of the coil by another smaller diameter (the second diameter). Core as used herein (also referred to as a xe2x80x9cplugxe2x80x9d) is intended to be broadly construed (as is xe2x80x9cplugxe2x80x9d) to include any material and shape which may be inserted into the coil. Materials, including plastic and aluminum, are selected to meet specific application requirements, to reduce vibration or to achieve artificial solid height. Other applications will be apparent to those with skill in the art from the teachings disclosed herein.
Another coiling machine according to the present invention includes a coiler adapted to form a coil having a first diameter and a plurality of reduced portions. The plurality of reduced portions include a first reduced portion and a second reduced portion wherein the second reduced portion is located a spaced distance from the first reduced portion. An insert device is positioned to insert a core in the coil between the first and second reduced portions. The first diameter may be between the reduced portions or to either side of them. The insert device includes transfer structure to transfer the core from a first position to a second position. The second position is adjacent to the coil for some applications, though in general it need not be.
Accordingly, the present invention envisions a coil comprising a length, a major diameter (generally as part of the coil body) defining an interior, and a first reduced portion. The core is inserted into the interior and maintained in the interior by the reduced portion. Alternative methods eliminating the need for reduced portions are also provided. Use of a deformable core is one such method.
The present invention encompasses numerous methods of manufacturing coils, including spring assemblies having cores. One method includes the steps of forming a first diameter section and forming a first reduced portion. A core is inserted into the coil so as to be between the first reduced portion and a subsequently formed reduced portion.
One method of the present invention for manufacturing a spring assembly includes providing a continuous stream of wire to a coiler and providing a continuous stream of cores to an insert device positioned in the coiler. The wire is coiled into a first reduced portion and into a coil body (or coil core) having a diameter sufficiently large to contain the core. The core is inserted through (or into) the coil body up to the first reduced portion or there about.
The coil body is generally located mid-length of the coil and the coils are generally spaced closer together (along the length of the coil) in the coil body. Variations will be apparent to those with skill in the art.
Other objects and advantages of the present invention will be apparent from the following detailed discussion of exemplary embodiments with reference to the attached drawings and claims.